The Mactaquac Dam is the largest hydroelectric dam in the Canadian Maritime provinces. Explore how Esri Story Maps was used to create a discussion tool about the dam’s future through October’s App of the Month – Before the Mactaquac Headpond.
Larissa Holman was completing her master’s degree in resource and environmental management under Kate Sherren, Associate Professor and Academic Programs Coordinator, at Dalhousie University when she first heard about the public consultations on the future of the Mactaquac Dam. Built in 1967, the concrete used to create the power station of the dam unfortunately contains an aggregate that expands when exposed to moisture, a condition known as Alkali-Aggregate Reaction (AAR). Because of this, the dam’s useful lifespan was determined to be shortened to 2030, and public consultation were held to determine if the dam should be rebuilt, decommissioned or removed.
To help encourage local discussions around these options and present the impact of the dam on the Saint John River, Larissa and Kate used the power of historical aerial imagery and Esri Story Maps to create Before the Mactaquac Headpond.
The story map is a virtual tour of the Saint John River before the installation of the Mactaquac Dam. When the dam was built, it flooded a 100-km headpond of agricultural land and farming communities. The story map illustrates the pre-dam landscape of the Mactaquac area, near Fredericton, NB, for those who were not around to see it. Each bookmark in this story map explores a featured location along the Saint John River and gives a different view of the headpond between the dam near Fredericton and the Town of Nackawic.
The swipe story map allows us to compare and contrast the landscape surrounding the Saint John River and analyze the environmental effects of the Mactaquac Dam.
The story map was created using the Story Map Swipe template with Swipe Series enabled. This template enables users to interact with two web maps or two layers of a single web map, depending on how you build your story. The app enables you to present a single view, or to develop a narrative showing a series of locations or views of the same maps. Having the Swipe Series enabled in the settings of the template allows you to harness the Story Map Series template as you are able to add in more than one map. This story map shows the path of the dam to further highlight significant areas where the dam has affected its neighbouring landscape.
“The story map added the ability to guide people along to visit parts of the river valley and animate these changes with historical photographs and a short description for each location.,” says Holman. “Many residents now live on the headpond and enjoy the beauty and recreational value it offers. The storymap is an opportunity for develop a deeper understanding of the river valley's history and how significantly the area was changed when the dam was put in.”
When configuring the app, Larissa used the current basemap from Earthstar Geographics and DigitalGlobe to compare to georeferenced historical photographs from 1962-1963. The historical photographs were sources from aerial photographs available from the New Brunswick Department of Natural Resources. Each section of the story map also includes descriptive historical information about the area highlighted, providing end-users of the app with insight on what the area was like before the dam was installed.
After Larissa completed her story map, it was distributed in the community through the local press and shared with different regional organizations. The story map became an effective tool for giving the public a glimpse of Mactaquac’s history and analyzing the effects of development on the area’s landscape.
As for the future of the Mactaquac Dam, in December 2016, it was decided that the dam will be maintained for its expected lifespan until 2068.
Check out the story map and leave a comment below on what you found most compelling about the app.
See the full version of the app.